Compatible: Disk filters are designed specifically for SDS 4.0 receivers. for wax guards filter only compatible with for ,for ,for Hansaton(Not suitable for er hearing aids) and Unitron hearing aids equipped with SDS 4.0 receivers. Function: for wax guards can prevent earwax, dust, oil, and moisture from clogging the hearing aids, prevent dust from entering the hearing aids, protect your hearing aids, and extend the lifespan of the hearing aids! Keep the hearing aids clean and your ears healthy. Quantity of Satisfaction: for wax guards filters kit has 3 packs, each pack containing 8 filters, for a total of 24 filters. Easy to Use: hearing aid filter consumables are very simple to use, when replacing, just rotate the disc slightly, use the detachable end of the disc to remove the old filter, and then install the filter on the hearing aid Color: Black Material: plastic Package Contents: 3 x Hearing Aid Wax Guards Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.